WASHINGTON - A bitter confrontation between the Clinton administration and the residents of Vieques, a small Caribbean island used as a bombing range by the U.S. military, has grown even more poisonous with the Navy's admission that it tested radioactive depleted uranium munitions on the island.

The Navy's acknowledgment last week that Marine warplanes fired 263
rounds of depleted uranium shells at the Vieques firing range during a
training exercise last February has prompted accusations the Navy is
ignoring health and environmental hazards posed by the munitions.

Activists also charge the Pentagon is covering up other incidents in which the
radioactive munitions were fired on the island, and a lawmaker has called for
a congressional investigation.

"The use of cancer-inducing depleted uranium on Vieques must be
investigated through federal hearings," said Rep. Jose Serrano, D-N.Y.

The Navy owns two-thirds of Vieques, a 52 square-mile U.S. territory just
off the coast of Puerto Rico. For more than 50 years, the U.S. military has
used a portion of its land as the main weapons firing range for its Atlantic
forces. Vieques' 9,400 residents living on the remaining third of the island
have long protested the exercises, charging the smoke, chemicals and other
residues from the munitions tests have poisoned the island's soil and water
and led to increased incidents of cancer and other diseases among the
civilian population.

The protests escalated dramatically last April after a bomb
killed an islander working as a security guard for the Navy and seriously
wounded four other civilians. Enraged, scores of Vieques residents invaded
the firing range and set up encampments on the contaminated, shell-pocked
landscape, refusing to budge until the Navy agreed to halt all its exercises
and leave the island for good.

With all weapons testing at a standstill, negotiations began between Clinton
administration officials and the Puerto Rican government, which supports the
protesters. Last month, an offer by Clinton to close down the firing range in
five years and to use only inert ammunition in the meantime appeared to form
the basis for a possible compromise solution.

Then came last week's acknowledgment from the Navy that it had fired depleted
uranium rounds on the island. The admission came nearly a year after the fact
in response to a Freedom of Information request filed by the Military Toxics
Project, a Maine-based group that monitors the military's impact on the
environment.

The acknowledgment has not only hardened the demands of Vieques residents;
it has also drawn in a entirely new battalion of critics  military whistle-blowers and health experts who claim that exposure to areas shot up with
depleted uranium munitions during the Persian Gulf War is a major cause of
so-called "Gulf War Syndrome" among American veterans. Now, they say,
residents of Vieques  all U.S. citizens  may be the newest known victims
of the same syndrome.

The Pentagon rejects these accusations, insisting the radioactivity of
depleted uranium is low and the expended shells pose little risk to health or
the environment.

The Web site of the Pentagon's Special Office for Gulf War Illnesses cites an
interview with Dr. Naomi Harley, a professor at New York University's School
of Medicine and an expert on radiation physics.

In the interview, Harley says the fine radioactive residue left by
expended depleted uranium shells is almost indistinguishable from the uranium
that occurs in soil naturally. She also maintains airborne
concentrations of depleted uranium in a war zone are too low to cause serious harm.

"You breathe in some uranium, but the risk is so low, it's very hard to
calculate," she said in the interview.

But Maj. Doug Rokke, an Army physician and former director of the Pentagon's
Depleted Uranium Project, who studied the health and environmental effects of
the radioactive munitions in Saudi Arabia and Kuwait after the Gulf War, says
his research has proven the opposite. Exposure to depleted uranium munitions
is highly dangerous, he says.

"If you inhale or ingest this stuff, you're going to have health problems
right away," he said. "It also contaminates soil and water."

"The Pentagon is not telling the truth about the health and environmental
hazards from depleted uranium shells used on Vieques," said Paul Sullivan,
executive director of the National Gulf War Research Center, a veterans'
organization that has researched the after-effects of the military's use of
depleted uranium munitions.

Sullivan, a Gulf War veteran, says the Pentagon is minimizing the hazards
surrounding depleted uranium shells because it has found these munitions so
effective on the battlefield.

A depleted uranium shell is a solid projectile, made up entirely of
uranium-238. Capable of piercing thick armor, the super-heated shell has
enormous destructive power, igniting anything in its path as it disintegrates
upon impact into fine aerosol particles.

On Vieques, where the prevailing winds blow from the firing range on the
eastern side of the island to the populated areas on the western side,
incidents of cancer among the residents are 26.7 percent higher than in
Puerto Rico, according to a 30-year study released by Puerto Rico's Health
Department several years ago. Another Health Department study in 1998 showed
there are no significant differences in behavior, such as smoking, between
Vieques residents and Puerto Ricans.

"There is no other way to explain this," said Dr. Rafael Rivera Castano, an
epidemiologist at the University of Puerto Rico. "In Vieques, there are no
factories that contaminate the air. The only explanation is the environmental
contamination we've found  lead, arsenic, chromium and now radioactive
contamination from depleted uranium  which only comes from the bombing and
exercises of the Navy."

Many critics suspect the Navy lied when it claimed its use of depleted
uranium munitions was accidental. They note such munitions are tightly
monitored and controlled under regulations that require anyone who requests such
ammunition to present papers proving he or she is authorized to handle it.

"Those rounds are well marked," said Bob Whistine, an officer at the U.S.
Army's Material Command at the Rock Island Arsenal in Illinois, where the
safety measures for depleted uranium munitions were developed after the Gulf
War.

Some also have strong suspicions that, contrary to the Navy's claim, last
February's live-fire exercise with depleted uranium was not a one-time
affair.

The Committee for the Rescue and Development of Vieques, one of several
protest groups on the island, filed a Freedom of Information request last
June, asking the Pentagon to account for any use of depleted uranium
munitions on Vieques from 1985 to the present time by all of the U.S.
military branches, along with any private companies and allied countries
whose armed forces also utilize Vieques as a weapons testing site. So far,
the group has received no reply.

"We're highly suspicious of the excessive delay in a providing substantive
response to our request," said Flavio Cumpiano, the group's Washington
representative.

Any disclosure of other incidents in which depleted uranium munitions were
used on Vieques could weaken the Navy's case for keeping its target range.
"The Navy is in the public eye right now, and what they say was a one-time
accident could be revealed to have been a pattern," Cumpiano said. "They
might be stalling until President Clinton makes a final decision on the
future of the Vieques firing range."

Meanwhile, Cmdr. Greg Smith, a Navy spokesman, said in the 2 1/2 months
between the February firing incident and the protesters' closure of the
Vieques test range in April, Navy experts had retrieved a total of 57 spent
bullets. The experts were unable to collect the remaining 206 radioactive
shells, he said, because of the presence of the protesters on the firing
range.

Though Smith described the firing range as a "hazardous area" and "a place where humans are not meant to be," he noted that further cleanup "is not being
currently addressed because there is no requirement to clean up the site at
this point."

Rokke calls such decisions "crazy," noting such decisions violate Nuclear Regulatory
Commission laws that require the military to clean up contaminated test sites. Rokke added experts could continue to collect spent depleted uranium munitions despite the presence of the
protesters.

"The fact that people are there on the firing range with more than 200 DU
bullets still unaccounted for is all the more reason to go in there and
provide environmental protection," Rokke said.

Sullivan, of the National Gulf War Research Center, said he believes the
Pentagon is ignoring the environmental cleanup requirements in Vieques
because such action would open the military to similar obligations in other test
sites.

"The minute they agree to clean up Vieques, they've got to clean
up the test sites in Okinawa, Nevada, Maryland and Indiana, not to mention
the live fire sites in Saudi Arabia, Kuwait and Kosovo," he said. "They don't
want to go there."